Is there a vent on the fuel tank, or is the gas cap the vent. Mine builds up a lot of pressure when sitting on a hot day. When I start it the car acts funny for the first minute. At the car show today I opened the gas cap after about an hour of sitting to relieve pressure, and it didn't have the startup issue.

There is a vent, via the charcoal canister setup. Too much pressure means there is something wrong there.

I have never had the problem, can't help beyond that.

There's 2 ways the pressure is controled. The purge solenoid (the black valve just to the rear of the TPS & IAC) is controlled by the ECM.

The vapor canister pressure control valve is on a line in the LH front fender near the vapor canister. You can test it by applying 15 in. vacuum to it. After 10 seconds, there should be at least 5 in.

Also with 15 in applied, you can disconnect the tank side of the valve, put a piece of tubing on that abd blow into it. With vac applied you should be able to feel the air pass thru the valve.

BTW, my 92 usually has some pressure when I stop at a gas station. The hotter it is, the more pressure, sometimes quite a bit.

I just walked out into the garage, zero press after sitting 2 days in cool weather.

You can also make sure the line from the gas tank to the canister isn't plugged.

Matthew

I now have charcoal bits everywhere. There was no pressure in the tank today. The startup problem only occurs when it has been sitting in direct sun for a few hours. I pulled the line from the tank to the canister and let charcoal fall out of it. Then checked it, there weren't any issues with it being clogged. The line to the purge valve also has a lot of charcoal in it. This line is not totally clogged, but I think it might be causing part of the problem.

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There is also a vent in the gas cap itself, which could (and have been known to) go bad...

Joe

I got a new canister today. Tomorrow I will try to get the line cleared and see if any charcoal is in the purge valve. Its gonna be a dirty job.

I have the new canister in and the line clear. My next question is the purge valve. With it off the car I was able to blow through it. Does it need voltage to be open or closed? Also it was clogged with charcoal too. I tried to get it all out, but I'm not sure if this ruined it.

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Probably voltage to open, but that's a guess.

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That's what I was thinking. I put it back on to see if the vacuum from the engine will help clean it out.